The present disclosure relates generally to flow meters and, more particularly, to a flow meter for measuring a flow rate of a flow of fluid.
Flow meters may be used in, e.g., a pulsed fluid flow system to determine a flow rate of a pulsed flow of fluid traveling through the system. In some instances, the flow meter determines the flow rate of the fluid by measuring a pressure drop across two defined points of a fluid channel formed in the flow meter, and calculating the flow rate based on the pressure drop measurement. Since pulsed flow of a fluid, such as, e.g., oxygen in an oxygen delivery system, includes substantially rapid (e.g., every 100 milliseconds or so) rising and falling flow rates per delivery cycle, the flow rate of the pulsed flow of fluid may be determined by first inducing laminar flow of the fluid through the flow meter. Then the pressure drop of the fluid across the device is measured, and the flow rate is calculated based on a linear relationship (due to laminar flow) with the pressure drop across the device.
Some of the flow meters currently used in pulsed flow systems include a laminar flow chamber to induce laminar flow of the fluid, which creates a substantially stable pressure drop across the flow meter. The laminar flow chamber may include several laminar flow channels formed by stacking several individual plates, often made of steel or other similar metals, in a very precise manner and forming a void space between them. Due to this precision assembly of several parts, mass production of these flow meters is generally very difficult, if available at all.